"Ordos is the first of a number of these ghost cities that will see similar magnitude price declines," says Gillem Tulloch of Asianomics.

The bigger issue, however, will be if declines reach the major cities. "The degree of price declines you are seeing in Kangbashi give a preview of what you will see in major cities. I would expect price declines of 20% nationwide over the next 1-2 years," Tulloch said.

Tulloch points to plunging transaction volume as evidence of a property slowdown. His firm expects a hard landing, with China slowing to zero GDP growth for several quarters.

You can see for yourself how many much excess real estate there is around China -- by some estimates as many as 64 million empty apartments. "It's like walking into a forest of skyscrapers, but they're all empty," Tulloch said of another ghost city, Chenggong.